Part of the 1379 Lay Subsidy Roll for Yorkshire has been transcribed and made available on Genuki, including the list for Owston: http://tinyurl.com/7w3ej2n . There’s no index but it might be worth searching through the individual parishes to see if you can pick up any references. The information was transcribed from The Yorkshire Archaeological and Topographical Journals (all pre 1900). The data is ”signed” J.G. 8th February, 1879. In the journals the data is given wapentake by wapentake, however this format makes very large files when placed on the World Wide Web, and so the data has been split into places, and then re-combined into parishes so that it can be accessed from the relevant Genuki parish pages eventually. Most of the information concerns the West Riding, however there is also most of the Ainsty wapentake and Howdenshire in the East Riding. The only information for the North Riding is for Humburton in Kirby Hill parish in the West Riding.